As onboard headlamps, instead of conventional halogen lamps, long-life, bright discharge lamps or light sources using LEDs come into wide use. At the same time, high-performance headlamps become widely available which have additional functions such as an AFS (Advance Front lighting System) or DRL (Daytime Running Light). Some of the high-performance headlamps have a function of informing a driver of an abnormal event of a headlamp. As a means for informing a driver of an abnormal event occurring in the vehicle, there is a warning light (alarm lamp) indicating an abnormal event visually or a warning sound (alarm buzzer) indicating an abnormal event aurally.
Patent Document 1, which relates to a system for informing a user of various abnormal events occurring in headlamps of a vehicle, discloses an abnormal event informing device for estimating and displaying the site of a malfunction including identification of a right or left light (headlamp).
Patent Document 2 discloses an onboard headlamp using a discharge lamp as its light source, which has an auxiliary light source provided separately from the discharge lamp, and lights it when an abnormal event occurs in the discharge lamp, thereby substituting it for the discharge lamp having a fault owing to the occurrence of the abnormal event.
Patent Document 3 discloses a light source lighting device with a communication function. The light source lighting device enables quick communication processing while executing the lighting processing appropriately even if the communication processing is performed during the processing of lighting the discharge lamp.
Conventionally, although apparatuses have been disclosed which integrate the lighting devices for lighting right and left headlamps of a vehicle as in the Patent Documents 1 and 2, there is none that arranges abnormal event informing paths, which are provided for informing an abnormal event occurring in the right and left independent headlamps, into a single path.
For example, in the Patent Document 1, a plurality of LEDs for informing a driver of an occurrence of a fault or an estimate result of a fault are provided corresponding to the right and left discharge lamps of the headlamps of a vehicle, so that an abnormal event occurring in a headlamp is indicated by lighting the corresponding LED. In the Patent Document 2, although it outputs a switching signal for lighting the auxiliary light source, it does not arrange the informing system of an abnormal event for the driver into a single system.
In addition, although the Patent Document 3 discloses communication processing with external equipment via a communication control unit provided in the lighting device, it does not describe a signal format for notifying an abnormal event informing device mounted in the vehicle of an abnormal event occurring in one of the right and left headlamp lighting devices of the vehicle in cooperation with the communication operation of the other lighting device.
As described above, although systems for informing of an abnormal event in detail in various ways are disclosed, when an abnormal event occurs in a headlamp of a vehicle, it will not matter much to a driver whether the abnormal event occurs in the right or left headlamp, but it will be enough for the driver to be able to identify that a headlamp has an abnormal event in the first place. To achieve this, as for informing a driver of a headlamp abnormal event, a single system that integrates right and left is enough, and hence it is necessary to reduce excessive functions of the conventional examples and to reduce the components involved with the reduction.
The present invention is implemented to solve the foregoing problems. Therefore it is an object of the present invention to provide a headlamp light source lighting device and a vehicle headlamp lighting system using the same capable of simplifying a configuration of an output system and reducing the amount of components necessary for the configuration by arranging the output system, which transfers information about an abnormal event detected with right and left headlamp light source lighting devices to an abnormal event informing device, into a single system, thereby being able to contribute to the reduction in the weight of the vehicle as a result.